Some mobile communication devices are now equipped with multiple wireless subscriber identity modules, allowing such devices to communicate over different communication networks. In a dual SIM dual active (DSDA) first communication device (“Phone X”), one subscription may be in active voice call (call#1) with a second communication device (“Phone Y”). During call#1 with Phone Y via a first subscriber network, Phone X may receive an incoming voice call (call#2) from a second communication device (“Phone Z”) on a different second subscriber network.
In the context where the first subscriber network and second subscriber network are different networks (e.g., implementing the same communication technology but different operators, implementing different communication technologies, etc.) there may not be away to notify the first subscriber network that call#1 has been placed on hold by Phone X. For instance, if the user of Phone X accepts the incoming call (call#2), the active call (call#1) is placed on a local hold state by Phone X, and call#2 between Phone X and Phone Z becomes active. For call#1, since it was placed in a local hold where no “HOLD” message, instruction, and/or command is sent to the first subscriber network by Phone X, then Phone Y is not informed that Phone X has placed call#1 in the local hold state. That is, while a network-initiated call hold (e.g., initiated by the first subscriber network) may permit informing Phone Y that call#1 has been placed on hold, there is no mechanism to inform Phone Y when Phone X performs a local call hold of call#1 without intervention of, or informing, the first subscriber network. Because the new call (call#2) is coming via the second subscriber network, the first subscriber network is not aware of the user-initiated call hold on Phone X and cannot inform Phone Y of the change of state for call#1.
Therefore, a solution is needed that permits informing a second communication device (Phone Y) operating on a first subscriber network when a call hold of a communication session (call#1) occurs that is not initiated by, and/or notified to, the first subscriber network.